|
Your array rotation problem has a fairly standard solution in a qualified
off-set of an array index:
data _null_;
call symput('_nobs',nobs);
stop;
set xx nobs=nobs;
run;
%macro shift(_trace=ON);
data xx (drop=i j);
array aa(&_nobs.) _temporary_;
do i=1 by 1 until(end);
set xx end=end nobs=_nobs;
aa((i ne _nobs)*i + 1)=a;
end;
do j=1 to _nobs;
a=aa(j);
output;
end;
stop;
run;
%if (&_trace.=ON) %then %do;
proc print;
run;
%end;
%mend shift;
%shift
%shift
%shift
%shift
One odd note: has anyone seen this Note?
NOTE: Line generated by the invoked macro "SHIFT".
1 data _null_; call symput('_nobs',nobs); stop; set xx
nobs=nobs; run;
----
546
NOTE 546-185: The variable nobs may be uninitialized.
Sig
-----Original Message-----
From: evan.cooch@NOSPAMCORNELL.EDU [mailto:evan.cooch@NOSPAMCORNELL.EDU]
Sent: Tuesday, October 15, 2002 5:01 PM
To: SAS-L@LISTSERV.UGA.EDU
Subject: weird sort problem | programming challenge
Must be late in the day, or the beer has run otu. One or the other ;-)
Suppose you have a data set, containing the following simple oridnal
sequence of numbers:
1
2
3
4
What I'm try to do is sequentially generate what I'll call
'frame-shift' sorts of these numbers:
4
1
2
3
then
3
4
1
2
then
2
3
4
1
leading back to
1
2
3
4
Any ideas how to do this (without using SQL)? I'm stuck...
Thanks!
| 
